Guys,
I have been running 351W heads on my 289 for about (oh my gosh!) ten years
now. I cc'd the heads - 59cc each cylinder. I first used flat-top TRW's
(nominal 10.5:1 compression). This gave me 9.3:1 actual compression. with
0.010 deck clearance, etc. Ran great, but took gobbs of advance; 45-50
degrees total!!. Previous motors with 289 heads and 10.5:1 liked about 36
degrees total. The 351W heads flowed better, but motor seemed to be crying
for more compression, so when I rebuilt it I used the TRW pop-up pistons
(nominal 12:1), which gives 10.9:1 actual. Everything else was identical,
including the cam which is the Ford Motorsport solid lifter. Engine runs
stronger with higher compression and even idles decent at 6-800 rpm, is
happy with 92 octane, and does not overheat. It still likes a lot of
advance though. I have set up my mech. dist. with 35 degrees advance and
set initial at about 12 degrees. Anyone else have my experience with the
351W heads needing more advance? I did a lot of porting and polishing of
the heads and chamfered every edge on the heads and the pistons.
Also, regarding the 351W heads' compatability with 289/302; these heads do
NOT necessarily require longer push rods. They are identical to the other
Windsor heads in this regard. The valve stems on stock 351W valves are
longer, so if you use 351W valves, of course you need 351W push rods. I
used the shorter stem valves used on the 289/302 which are actually
stainless valves for a Chevy application. Having shorter valve stems means
more clearance, which is definitely an issue with a Tiger. I use the
standard chrome valve covers (sans baffles) and can get them on an off
easily, enabling me to adjust valve clearance in less than an hour.
>In a message dated 97-08-23 12:21:47 EDT, laifman@flash.net writes:
>
><< Compression ratio needs
> attention also. In addition, water passages between block and head are
> in different places and require drilling new ones in the head. Oh, dit I
> mention push rod length? >>
>Guys,
>I ran the DOOE casting 351w heads on a 289 for several years, and while it is
>true that you must use different pushrods as well as head bolts with washers
>under them (or the original style with the washers built on to the bolts),
>you should have no problems with piston clearance with a stock cam. I know of
>no holes that need to be drilled in the heads, but there IS a difference in
>the way the water passages are shaped at the end of the heads. This requires
>the use of 351 manifold gaskets.
>The combustion chambers are larger than the 289 heads which lowers
>compression some, but if the block is decked to the minimum .0015 piston/top
>of block clearance, this should not be a problem. The heads breathe for
>better than the stock 289 heads.
>Ray
>
>
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